JPH06218913A - Transfer medium - Google Patents

Abstract

PURPOSE:To realize an ink jet recorder which can obtain a transfer medium capable of realizing a uniform temperature distribution by uniformly heating and a high quality transfer image. CONSTITUTION:A transfer drum 1 has a black-made area 13 wherein an end part of a green pipe 11 having a metallic luster face on an inner surface is processed by a treatment for making black, and contains a heater lamp 4 in its inside. An end part of the heater lamp 4 is little in radiation quantity, and both end parts of the transfer drum radiate heat via a bearing 16. An energy absorption amount from the heater lamp 4 increases in the black-made area 13, and the transfer drum 1 can obtain a uniform temperature distribution. When a transfer type ink jet recorder is formed by means of the transfer drum, uniform heating can be carried out with the heater lamp 4 of the same length as that of the transfer drum 1. An ink drop discharged on the transfer drum 1 is pressure transferred to recording paper 5 in a uniform dry condition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer medium and a transfer type ink jet recording apparatus using the transfer medium.

[0002]

2. Description of the Related Art A transfer type ink jet printer is characterized in that it does not cause ink jet clogging caused by unintentional contact between recording paper or paper dust and a recording head, and high reliability is obtained. As such a transfer type ink jet printer, there are US Pat. No. 4,538,156, US Pat. No. 5,099,256, and JP-A-62-9284.
The configuration described in Japanese Patent Publication No. 9 is known.

In these apparatuses, an ink jet recording head (hereinafter referred to as a recording head) having a plurality of nozzles is provided on a cylindrical transfer medium with a gap therebetween. The transfer medium is composed of a metal tube and an elastic layer covering the metal tube. Silicone rubber or silicone rubber containing iron oxide is used as the elastic layer. The recording step includes a writing step of writing an ink image on a transfer medium and a transfer step of transferring an ink image onto the recording sheet by bringing a recording sheet, which is a recording medium, into contact with the transfer medium and pressing from behind. ing.

In the structures described in US Pat. No. 5,099,256 and JP-A-62-92849, a step of heating an ink image on a transfer medium prior to transfer is provided. This is to remove the ink solvent content on the transfer medium to dry the ink image and prevent image deterioration due to ink permeation into the recording paper at the time of the ink image transfer.

As a heater, a rod-shaped heater lamp is provided to irradiate light to heat the transfer medium.

[0006]

The quality of the ink image on the recording paper depends on the dryness of the ink image on the transfer medium. Therefore, in order to keep the dry state on the transfer medium uniform, making the temperature of the transfer medium uniform irrespective of the location has been a problem for stably obtaining high image quality.

When the transfer medium drum is heated by using a rod-shaped lamp, if the lengths of the transfer medium drum and the light emitting portion of the lamp are substantially equal to each other, the temperature distribution in the axial direction of the transfer medium becomes
As shown in FIG. 9, it has a flat maximum value at the central portion and sharply decreases at positions close to both ends. This is because the transfer medium and the lamp are separated from each other by a certain distance, so that the central portion of the transfer medium is irradiated with a larger amount of energy per unit length in the axial direction than the end portion. Further, since heat dissipation is promoted at the end portions of the transfer medium, the temperature drop at both end portions is remarkable.

Therefore, in order to obtain a somewhat uniform temperature distribution in the axial direction on the drum with such a structure, the transfer is performed by using a lamp having a length sufficiently larger than the axial length of the transfer medium drum. It is necessary to configure a region in which the energy irradiation amount per unit length in the axial direction of the medium drum is substantially equal to the recording region of the drum. A heat fixing device of an electrophotographic copying machine is known as a configuration in this case. That is, as shown in FIG. 10 as a representative example, the structure described in Japanese Utility Model Publication No. 58-46417 is used as a drum 1
A heater lamp 102 having an axial length of 01 or more is incorporated.

The heating method such as the heat fixing device of the electrophotographic copying machine shown in FIG. 10 has an unavoidable drawback. First, the first
In addition, since the heater lamp having a width larger than the recording area and the supporting and energizing portions for the heater lamp are required, the device becomes large. And
Secondly, the accuracy of the distance between the transfer medium drum and the recording head and the relative speed of the transfer medium drum with respect to the recording head deteriorates. Particularly regarding the second drawback, it causes a serious defect in the print quality of the ink jet recording apparatus.
That is, in the transfer type inkjet recording apparatus, in order to land the ink droplets at a predetermined position, it is necessary to control the transport speed of the transfer medium and the distance between the transfer medium drum and the recording head with high accuracy.

Therefore, the outer diameter of the transfer medium drum must be controlled with high accuracy, in particular, the outer diameter deviation from the rotation support portion should be small, and the rotation speed should be controlled to a predetermined speed. Therefore, it is necessary to ensure accuracy by using a structure in which both ends of the transfer medium drum are supported by bearings. However, when a heater lamp having a length equal to or longer than the axial length of the cylindrical transfer medium is incorporated like a heat fixing device of an electrophotographic copying machine, it is difficult to control dimensions and ensure accuracy.

The present invention has been made from the above viewpoint, and provides a transfer medium and a high-quality transferred image that can be uniformly heated and realize a uniform temperature distribution while satisfying the above-mentioned restrictions on the apparatus configuration. It is to realize an inkjet recording apparatus that can be obtained.

[0012]

The transfer medium of the present invention is characterized in that it has an energy absorbing portion having an energy absorption rate higher than that of the central portion at the end portion.

Further, the ink jet recording apparatus of the present invention comprises a recording head capable of selectively controlling ejection of ink droplets,
It has the transfer medium that temporarily carries the ink droplets ejected from the recording head, a heating unit that heats the ink droplets on the transfer medium, and a transfer unit that pressure-transfers the ink droplets on the transfer medium to the recording medium. Is characterized by.

[0014]

With the above construction, a uniform temperature distribution can be obtained by intentionally increasing the energy absorption rate of the portion of the transfer medium where the irradiation energy from the heating means is small or where the heat radiation is large. Further, by forming a transfer type inkjet recording device using this transfer medium, the dry state of the ink image on the transfer medium is made uniform,
It is possible to transfer to a recording medium, and a high quality transferred image can be obtained.

[0015]

EXAMPLES The ink jet recording apparatus of the present invention will be described below with reference to examples.

FIG. 1 shows a perspective view of the ink jet printer of the first embodiment. An inkjet recording head 2, a backup roller 3 as a transfer unit, a heater lamp 4 as a heating unit, and a temperature sensor 6 as a temperature detection unit are sequentially arranged around a transfer drum 1 as a transfer medium. The heater lamp 4 is controlled by a heating control unit including an output signal processing circuit 7 and a heating drive circuit 8 for lighting the heater lamp. The directions of rotation and movement of each member are indicated by arrows A, B, and C.

The recording head 2 is an ink jet recording head, and has a plurality of nozzles which are separated from each other by a predetermined distance in the axial direction of the transfer drum 1. Upon receiving the ink supply from the ink container 21, the ink droplets are ejected.

The transfer drum 1 is formed by laminating a fluorosilicone rubber as a surface layer 12 around an aluminum tube 11 made of a good heat conductor. The surface layer 12 is not limited to fluorosilicone rubber, and it is desirable that the surface layer 12 has a property of easily peeling an ink image. Fluorosilicone rubber is
It has low surface energy and high peelability. As shown in FIG. 2, a substantially central portion 20 of the inner peripheral surface of the transfer drum 1 has a metallic glossy surface, and a shaft end portion having a high energy absorption rate (in this embodiment, black paint is applied to blacken the surface). It has a treated blackened area 13). The shaft end portion of the transfer drum 1 is supported by a support shaft 14 via an insulating bearing 15. The bearing 15 is electrically insulated from the frame 17 by an insulating bush 16 and fixed to the frame 17.

FIG. 2 shows a developed state of the inner peripheral surface of the raw tube 11, showing the shape of the blackened region 13 provided at the end of the shaft. It is shown in a state of being developed vertically with respect to the center line.

The heater lamp 4 is a rod-shaped halogen lamp, is housed inside the transfer drum 1, and is supplied with electric power through a contact 18 built in the support shaft 14. The heater lamp 4 irradiates the inner surface of the transfer drum 1 with light to heat the inner surface.
A part of the transfer drum 1 does not have a surface layer, and the temperature sensor 6 directly contacts the raw tube 11 to detect the temperature. The output of the temperature sensor 6 is input to the heating drive circuit 8 via the output signal processing circuit 7. Here, the transfer drum 1 is controlled to be kept in a predetermined temperature range by changing the energization state of the heater lamp 4 in accordance with the temperature of the transfer drum 1.

The backup roller 3 is a metal roller made of aluminum and is configured to be pressed against the transfer drum 1 by a load device (not shown). In the transfer step, the transfer drum 1 is pressed through the recording paper 5 which is a recording medium. The transfer load is about 10 kg in this embodiment.

As the ink, one whose viscosity is increased by the evaporation of the solvent or which has elasticity is used. In this embodiment,
A pigment is used in a semi-dissolved state together with an additive such as a surfactant in pure water as an ink solvent together with a colloidal dispersion type resin. Specifically, as a pigment, carbon black dispersion liquid (carbon black solid content 20 wt%) 15 wt%, colloidal dispersion resin (resin solid content 40 wt%) 30 wt%, triethanolamine 5 wt%, polyethylene glycol 5 w
t%, surface-active agent 2 wt%, and preservatives, etc.
An ink prepared by adding t% is used.

Next, the operation will be described.

While the apparatus is on standby, the transfer drum 1 is stopped,
The heater lamp 4 is also kept off. At the start of the printing operation, the heater lamp 4 is turned on and the transfer drum 1 is heated to a predetermined temperature by the control operation described above.

When the transfer drum 1 reaches a predetermined temperature, the transfer drum 1 is started to rotate by the driving means 19. Next, ink droplets are selectively ejected from a plurality of nozzles of the recording head 2 to which ink is supplied from the ink container 21, and an ink image is recorded on the transfer drum 1. The transfer drum 1 carrying an ink image is kept at a predetermined temperature by a heater lamp 4 and a control means for driving and controlling the heater lamp 4. As a result, the water, which is the main component of the ink solvent, is removed from the ink image on the transfer drum 1 to obtain a dry ink image, and the transfer process is started.

In the transfer step, the recording paper 5 is fed by a recording paper conveying means (not shown), brought into contact with the transfer drum 1, and pressure is applied by the backup roller 3, and the ink image on the transfer drum 1 is applied by the pressure. Transfer to 5. When the recording operation is completed, the heater lamp 4 is turned off.

In the apparatus of this embodiment, the transfer drum 1 has a blackened region 13 which has been blackened by applying black paint to the end portion of the shaft. In the shaft end portion, the irradiation energy per unit length in the axial direction of the transfer drum 1 is relatively smaller than that in the central portion, and heat is radiated through the support shaft 14, but the blackening treatment absorbs light at the end portion. The rate is increased to keep the temperature in the axial direction of the transfer drum 1 uniform. Irradiation distribution of heater lamp 4, heat dissipation distribution of transfer drum 1, transfer drum 1
3 shows the energy absorption rate distribution and the temperature distribution of the transfer drum. The energy absorption rate distribution 30 has a relationship to compensate for the irradiation amount distribution 31 of the heater lamp 4 and the heat radiation distribution 33 of the transfer drum 1, so that the blackened region 1
3, the transfer drum 1 exhibits a substantially uniform temperature distribution 32.

4, 5, 6, and 7 show other examples of the shape of the blackened region 13 on the inner surface of the transfer drum 1. In FIG. 4, the blackened region 13 on the inner peripheral surface of the raw tube 11 of the transfer drum 1 has a comb-shaped pattern. By doing so, the blackened area ratio can be selected according to each position so as to compensate the irradiation amount distribution of the heater lamp 4 and the heat radiation characteristic of the transfer drum 1 in the axial direction of the transfer drum 1. In FIG. 5, the blackened region 13 has a wedge-shaped pattern. In FIG. 6, the blackened regions 13 are formed by scattered dots. In the transfer drum shown in FIG. 7, the optical density of the blackened area 13 is gradually changed. These patterns can be obtained by applying a black paint or by adhering a black film. Further, the color forming the pattern is not limited to black in particular, and if the absorption rate of light from the heater lamp 4 is higher than that of the base material of the transfer drum 1,
The effect is obtained. Furthermore, if the paint or film having a lower absorption rate than the base material of the transfer drum 1 is used, as shown in FIGS.
The same effect can be obtained by drawing a pattern obtained by reversing the pattern shown in FIG.

A second embodiment of the present invention is shown in FIG. In the apparatus of this embodiment, the surface layer 1 of chloroprene rubber is formed on the aluminum tube 11 having a metallic luster inner surface as a transfer drum.
2 is laminated. The chloroprene rubber of the surface layer 12 has a blackened region 13 which contains carbon black at its end and is blackened. As a heating means for the transfer drum 1, a heater lamp 4 is provided in the vicinity. The point that the transfer drum 1 is heated by irradiation with light from the outer periphery is different from the first embodiment.

The transfer drum 1 receives a non-uniform light irradiation with a large irradiation amount at the central portion thereof, and further the temperature is lowered at the shaft end portion of the transfer drum 1 due to heat dissipation due to heat conduction. In order to compensate for this, a blackened region 13 that has been blackened is provided at the end to increase the light absorption at the end. As a result, the transfer drum 1 has a uniform temperature distribution. The pattern of the blackened region 13 used here can also be the pattern as shown in the first embodiment. Further, when the surface layer 12 is thin or semi-transparent and can sufficiently transmit light, a blackened region can be provided inside the surface layer 12 or on the outer peripheral surface of the tube 11.

Although the rod-shaped lamp is used in the two embodiments described above, it is not always necessary to use the rod-shaped lamp. For example, a spherical halogen lamp may be installed in the aluminum base tube 11 or in the vicinity of the outer side of the aluminum base tube 11, which is also effective.

If further added, a halogen lamp
When the radiant energy of a xenon lamp, incandescent lamp, etc. is not limited to an energy radiator that is an electromagnetic wave in the range from infrared to visible light, but other wavelengths / forms such as microwaves are used for overheating. However, the effect can be obtained by providing the distribution of the energy absorption rate.

In the structure of the above-mentioned embodiment, when the blackened region is blackened, the blackened region is quickly heated during the heating operation, and the heating efficiency can be increased. Further, since the heating characteristics of the transfer medium can be partially controlled to realize a uniform heat distribution, it is not necessary to support the transfer medium by a good conductor having a large thickness, and the weight can be reduced. Further, as far as the second embodiment is concerned, since the raw material pipe of the transfer medium can be made of a heat insulating material for the same reason, the heat radiation amount can be reduced and the energy required for temperature rise can be reduced. .

[0034]

According to the present invention, a uniform temperature distribution can be obtained by intentionally increasing the energy absorption rate of the portion of the transfer medium where the radiant energy from the heating means is small or the portion where the heat radiation is large. It has an effect that a transfer medium can be realized. Further, by constructing a transfer type ink jet recording apparatus using this transfer medium, it is possible to heat the transfer medium with an energy radiator equal to or shorter than the transfer medium, so that it is possible to support the transfer medium while maintaining dimensional accuracy. Become. Further, it is possible to make the dried state of the ink image on the transfer medium uniform and transfer it to the recording medium, and it is possible to realize an inkjet recording apparatus capable of obtaining a high quality transferred image.

[Brief description of drawings]

FIG. 1 is a perspective view of an ink jet printer showing a first embodiment of the present invention.

FIG. 2 is a development view showing the shape of a blackened region of a transfer drum used in the inkjet printer according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a dose distribution of a heater lamp used in the first embodiment of the present invention, a heat radiation distribution of a transfer drum, an energy absorption rate distribution, and a temperature distribution of the transfer drum.

FIG. 4 is a development view showing a second shape of a blackened region of a transfer drum used in the inkjet printer according to the first embodiment of the present invention.

FIG. 5 is a diagram showing an example of a third shape of a blackened region of a transfer drum used in the inkjet printer of the first embodiment of the present invention.

FIG. 6 is a diagram showing an example of a fourth shape of a blackened region of a transfer drum used in the inkjet printer of the first embodiment of the present invention.

FIG. 7 is a diagram showing an example of a fifth shape of a blackened region of a transfer drum used in the inkjet printer of the first embodiment of the present invention.

FIG. 8 is a perspective view of an ink jet printer showing a second embodiment of the present invention.

FIG. 9 is a diagram showing a temperature distribution in the axial direction of a transfer medium according to a conventional example.

FIG. 10 is a diagram showing an example of a configuration of a heat fixing device of the electrophotographic recording apparatus.

[Explanation of symbols]

 1: Transfer drum (transfer medium) 2: Recording head 3: Backup roller (transfer means) 4: Heater lamp (heating means) 5: Recording paper (recording medium) 13: Blackened area 20: Central part

Claims (8)

[Claims] 1. A transfer medium which is heated by receiving radiant energy from a heating means, wherein an end portion is provided with an energy absorption portion having a higher energy absorption rate than the central portion. 2. The transfer medium according to claim 1, wherein the energy absorbing portion is formed by changing a color between a central portion and an end portion. 3. The transfer medium according to claim 2, wherein the color change pattern is a pattern in which the energy absorption rate gradually changes. 4. The transfer medium according to claim 3, wherein the pattern has a comb shape, a wedge shape, or a dotted shape. 5. The transfer medium is composed of a tubular body, the heating means is arranged inside the tubular body, and the energy absorbing portion is formed on an inner peripheral surface of the transfer medium. The transfer medium according to claim 1, 2 or 3 or 4. 6. The energy transfer section is configured such that the transfer medium is composed of a cylindrical tube and a surface layer provided on an outer peripheral surface of the tube, and heating means is arranged so as to be close to the surface layer. Is formed on the surface layer of the transfer medium, The transfer medium according to claim 1, 2 or 3 or 4. 7. The transfer medium is composed of a cylindrical tube and a surface layer provided on the outer peripheral surface of the tube, and a heating means is disposed so as to be close to the surface layer, and the surface layer is provided. 5. The transfer medium according to claim 1, wherein the energy absorbing portion is formed on the inner surface of the surface layer of the transfer medium or the outer peripheral surface of the raw tube, the light absorbing material being formed of a material capable of transmitting light. 8. The transfer medium according to claim 1, wherein the transfer medium is made of a heat insulating material.